Mid winter pond change

Baytown, TX(Zone 9a)

Hello all. I just came across this forum this morning and enjoying it very much. Lots of knowledge freely shared. Here's my situation. This past spring, I put in a small (bathtub size) pond with two goldfish and a Koi. The fish have done well. Last week, I noticed that the water level dropped considerably overnight, so figured I had developed a leak in the preformed liner. Since my Koi has grown to nearly a foot in length, I had already decided to build a larger pond next Spring, but the leak hastened things along.

So, yesterday, I put the fish in a #3 washtub, pulled out the old liner and dug a new pond that is roughly 8'x10' and about 2 1/2 deep (Luckily, I have a small tractor with front end loader for digging). I bought a flexible PVC liner from Home Depot, put it in and filled it with water. Of course, I still have to lay the rocks and build my waterfall.

I have a question: How soon can I put the fish into the new pond, and what do I need to do to prepare the water. The Koi has already jumped out of the tub and into the new pond. I just happened to see him do it, so netted him out and put him back into the tub and put a piece of chain link fencing over the tub to keep him from jumping out again. I hope the couple of minutes he was in the chlorine water didn't hurt him.

OK, one more question: I was using the #3 washtub to hold water overnight so the chlorine would weather off. Now, I fear I will need to add more water per day than the tub will hold. Since I am on city water with chlorine, what is a good way to do this.

I'm pretty well clueless to the proper way of doing things, but looking forward to getting educated on this forum. I have been fortunate so far to have three healthy fish.

Thanks in advance for letting me ramble.


Deer Park, IL(Zone 5b)

There are products you can add to the pond or water to eliminate the chlorine. Go to a local pond shop or online and order some asap!

Dolores, CO(Zone 5b)

You can find 'de-chlor' or a similar product at almost all petco's or petsmarts, or pet stores that eliminates the chlorine. It works immediately. You will need it always as you add water to your pond. good luck! Let's see pictures!


Baytown, TX(Zone 9a)

Thanks for the replies. Actually, I have some dechlorinator that I use occasionally if I need extra water (such as when my liner springs a leak). So, are you saying I can add water with a water hose, then add the dechlorinator? I guess I have been stressing too much about the fish being in chlorinated water since I have heard that they don't tolerate it at all.

How about the bacteria that ponds need? Or will my existing pump and filter have enough of it to start the new pond?

And, how long before I can introduce the fish to the new pond?

Of course, I guess they can't do much worse than being couped up in a #3 washtub, anyway. I just hate to think about having them die. I have them eating out of my hand, and tha's pretty special to me.

I know I am full of questions that I should have known the answers to before I ever got my first fish, but it was done in ignorance.

I'll try to get pics tomorrow. Of course, it's not pretty right now. Just a lot of mud and mess. It had rained all day today, so didn't get anything done.


Dolores, CO(Zone 5b)

dgal, I'd venture to guess that you are no different than most of us when we decided we wanted a pond. I think most of us jumped in before knowing it all (or any of it, LOL!). That's why DG is awesome... lots of very knowledgeable folks sharing information and inspiration.

Yes, you can fill the pond with tap water, add the de-chlor as it is going in. As it is all new, I'd wait a day or so before adding the fish. I'm pretty sure others here with way more knowledge will chime in with acclimating the fish and the general adjustments the pond will probably go through.



How big is a #3 washtub? My concern is that it is small and that there could be some problems with the fish using up the oxygen in a smaller tub faster than they do a larger pond..... I would use the dechlor in your new pond, following the package directions for the amount of gallons.

Are you running any pumps into the new pond? You need to figure out how long it takes for your pumps to turn over the entire amount of gallons in your pond and wait that period of time, to make sure your water is properly oxygenated. For example if your pond is 500 gallons and your pump turns over 250 gallons/hour, it will take 2 hours for your whole pond to be turned over and run through your pump.

I have seen where the suggestion is that there are several weeks that are typically allowed with water circulating, but I believe that is so the good bacteria will start to colonize. The good bacteria will not start to colonize unless your water temperature is consistently 55 degrees or above. I don't know about your zone, but my pond water will not be consistently above 55 degrees for another couple of months.

Do you know what your water temperature is in your wash tub and your water temperture in the larger pond? At this point in time, if you water is oxygenated, you have the dechlor in the pond, and it will be awhile before your good bacteria starts to colonize, I would find a very strong plastic bag that is large enough to accomodate your fish and then I would put them into the bag, close it and then I would float the bag full of fish in your new pond for 20-30 minutes so the temperatures are about the same and then I would release the fish into their new home......

Baytown, TX(Zone 9a)

As promised, here is my new pond as it looks today. It has rained the last two days, so is really a muddy mess now.

Thumbnail by dgal
Baytown, TX(Zone 9a)

Every ponder needs one of these little jewels. It is a life saver. Of course, Bo, the Frisbee dog had to get in the picture. He is a five year old Australian Shepherd.

I am retired, but do some tractor work in the warmer months and a professional Santa in Nov/Dec.


Thumbnail by dgal
Dolores, CO(Zone 5b)

Nice tractor! I sure miss having our bobcats. Those can do most anything.


Very nice! I love your pond. Can't wait to see it with some fish in it!

Baytown, TX(Zone 9a)

Yeah, I like those Bobcats too, Savage. A friend of mine has one with a machine on it that eats trees. I mean the whole thing. He grings them off at about the 12 foot level, grinds the stump down blow ground level, then straddles the fallen tree and grinds it up; all in just a few minutes. I call it his Bobcat on steroids.

And thank you, Carolyn. Actually, the fish are now in the pond as of late this afternoon. I am on my way right now to see if PetSmart has any of the beneficial bacteria to help things get started. Once I get the rocks in place and at least a few plants going, I'll post another picture. You should see it during the summer months. I have head high Elephant Ears and Banana trees growing around it. I can't wait!

This is a picture of the one I just took out.


Thumbnail by dgal
springfield area, MO(Zone 5b)

Beneficial Bacteria to my understanding is only going to be viable if it has been kept refrigerated?

You might google that.
also I think that chlorine may dissipate from the water in a day or two without adding anything to the water.
You can probably google that too and find out more. I do think most dechlor products also neutralize copper and other stuff...

Baytown, TX(Zone 9a)

Oh Frilly, I just bought a bottle of it off the shelf at PetCo and it wasn't refrigerated. It was really for aquariums, but will treat 500 gallons if I use the whole $15 bottle. I'm probably just being paranoid, but wanted to get the bacteria introduced, not that it will do much good, since someone said the bacteria is dormant anyway until the water temp gets above about 55 degrees. Thanks for the heads-up. I will sure check on that.

I'm with you on the chlorine thing. My question was about adding water that I lose due to evaproation, and whether I could just throw the water hose in to top it off and put in some dechlorinator at the same time. I went ahead and threw some in a few minutes before I transferred the fish just because. I wasn't really worried about chlorine after sitting for a couple of days, and we have had an inch or two of rain during that time too.


springfield area, MO(Zone 5b)

I just top mine off, I never add dechlor to that. Now if I do a huge water change and I want to add the fish right away, then use you need to use it.

Holland, OH(Zone 5b)

You can add dechlor as you add water to the pond and there will be no ill effects for the fish. Fish can tolerate a water addition up to 10% of the pond's total water volume before chlorine reaches a level that is harmful.

That being said, what you must be aware of are chloramines, different than chlorine and much more lethal to all fish. There aren't too many municipal water systems that use chlorimines but you should make absolutely certain that yours isn't one of them. Most water conditioners neutralize both chlorine and chloraimine.

What does bother fish in a water change is a sudden pH change even, if it is in the safe range that koi tolerate. Koi prefer a range of 7.2 to 7.5 even though they will do fine in between pH 6.5 to about 8.2. What they don't like is an abrupt change even inside their normal tolerance range. Just a change of 0.3 can have their skin irritated and cause the koi to flash. I have a huge problem with that here. Our municipal water comes out of the tap at 9.5. In twenty four hours that pH drops to 8.2 , all on its own, just standing in a glass! I've talked to the folks in the lab that treat and test our municipal water and they say that's to prevent corrosion in the pipes. They add a buffer to the water that holds the pH at 9.2 or so. The buffer dissipates once the water leaves the tap. Makes a big pond water change a big problem. Add the complicating factor that rainfall naturally reduces the pond pH even more and going from rainwater softened pond pH 7.2 to tap water 9.2 is a change of 2000 units. Very, very hard on the koi. Know you pH. Test before and after a big rain and before and after a water change. If your not seeing big swings then consider yourself lucky and don't mess with the pH. Always add water to the pond slowly. It's less shock to the fish.

Baytown, TX(Zone 9a)

Great info Frilly and Snap. I'll be proficient at this koi keeping yet. We had another inch or so of rain last night and the pond actually overflowed. The fish are still swimming, so so far, so good. I am going to test the water later today.

Man! I don't know if I should have found this DG site. So many interesting forums; so little time.


(Mary) Anchorage, AK(Zone 4b)

Sounds like you need an overflow on that pond. When mine was put in, they dug a hole behind the skimmer box and filled it with rock then dirt. If my pond gets too full, it overflows into the 'dry well' they created. I also have a tiny hose that connects from my back faucet, runs underground to the skimmer and attaches to a gizmo like what you have in your toilet tank. If the water level drops too far, it turns on the spigot and fills it back up. Our tap water is pretty safe for the fish. You might try looking at koiface.com. I found that this last winter and they have really neat discussions just like here, only about ponds and fish. I found out that I am just one of many who have dove right in, sunk a few times, and am paddling like mad to learn about ponds and fish and plants. A bit of a challenge in Alaska. I try not to get too overboard on the 'additives' but some are simply necessary in a created pond environment. I have koi, goldfish, and shebunkin. And they stay in the pond all winter. This is the third winter and I think I may have it figured out. Your problems will be entirely different. Good luck.

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